Yeon Jun Jeong

Synthesis, characterization, and mineralization of polyamide-6/calcium lactate composite nanofibers for bone tissue engineering

Polyamide-6 nanofibers containing calcium lactate (CL) on their surface were prepared by neutralization of lactic acid (LA) in core-shell structured polyamide-6/LA electrospun fibers. First, simple blending of LA with polyamide-6 solution was used for electrospinning which interestingly formed a thin LA layer around polyamide-6 nanofibers (core-shell structure) and then subsequent conversion of this LA into calcium lactate via neutralization using calcium base. FE-SEM and TEM images revealed that plasticizer capacity of LA led the formation of point-bonded structure due to the formation of shell layer of LA and core of polyamide-6. The bone formation ability of polyamide-6/calcium lactate composite fibers was evaluated by incubating in biomimetic simulated body fluid (SBF). The SBF incubation test confirmed the faster deposition of large amount of calcium phosphate around the composite polyamide-6/calcium lactate fibers compared to pristine polyamide-6. This study demonstrated a simple post electrospinning calcium compound coating technique of polymeric nanofibers for enhancing the bone biocompatibility of polyamide-6 fibers.

Fetal topohistology of the mesocolon transversum with special reference to fusion with other mesenteries and fasciae

The developing mesocolon transversum was investigated using hematoxylin and eosin‐stained semiserial sections derived from 17 human fetuses between 12 and 30 weeks of gestation. The mesocolon was attached to the mesoduodenum and greater omentum until 12 weeks. However, the fetal duodenal attachment appeared not to correspond to the right colic flexure in adults. The greater omentum and mesocolon were likely to be irregularly folded at the attachment site possibly because the developing transverse colon “ran into” and pushed up the greater omentum and pancreatic head. Lymphatic vessels invaded the indistinct fusion plane to destroy the primary configuration. Moreover, the mesocolon seemed to “seize” or take‐over some parts of the splenic side of the greater omentum, but the thick gastric side containing the right gastroepiploic artery and vein remained along the greater curvature. Until 20 weeks, the left colic flexure was fixed to the pancreatic tail, and near the flexure the mesocolon also fused with the renal fascia. The left splenic end of the greater omentum was folded and fused together to form a thick ligament‐like structure, i.e., the gastrocolic ligament. In addition, near the duodenojejunal junction, a peritoneal bridge was often seen containing the inferior mesenteric artery or vein. Although surgeons generally believe that the mesocolon can be gently detached from the greater omentum, the fusion plane in adults appears to be the result of secondary modification and simplification by vascular development. Clin. Anat. 22:716–729, 2009.

Hispidin analogue davallialactone attenuates carbon tetrachloride-induced hepatotoxicity in mice.

In this study the protective effects of davallialactone (1), isolated from Inonotus xeranticus, have been examined against carbon tetrachloride (CCl₄-induced acute liver injury. Mice received subcutaneous injection of 1 (2.5, 5, and 10 mg/kg) for three days before CCl₄ injection (1 mg/kg). Protection from liver injury by 1 was confirmed by the observation of decreased serum transaminases and diminished necrosis of liver tissue. Reduced hepatic injury was very similar to that observed with silymarin, a known hepatoprotective drug used in this work for comparison. The groups treated with 1 had reduced reactive oxygen species (ROS), reduced serum malonyldialdehyde levels, and increased levels of liver Cu/Zn superoxide dismutase, as compared to the CCl₄ control group. The expression of heme oxygenase-1 in the liver tissue was increased and the activity of liver cytochrome P4502E1 was restored in the mice treated with 1. In addition, levels of serum tumor necrosis factor-alpha (TNF-α), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2), numbers of macrophage, and cleaved caspase-3-positive hepatocytes were reduced in the groups treated with 1. These findings suggest that davallialactone has protective effects against CCl₄-induced acute liver injury, and this protection is likely due to the suppression of ROS-induced lipid peroxidation and inflammatory response.

Ileal duplication cyst: Y-configuration on in vivo sonography.

Although the double wall or muscular rim sign is considered to be a characteristic sonographic imaging finding of an enteric duplication cyst, this sign can also be produced by Meckels diverticulum and sonographic artifacts. The Y-configuration on in vitro sonography has been reported to be useful for the definitive diagnosis of an enteric duplication cyst. Here, we report a case of an intraoperatively confirmed ileal duplication cyst that was correctly diagnosed before by identification of the Y-configuration on in vivo sonography.

Torsion of a mucocele of the vermiform appendix: a case report and review of the literature

Torsion of a mucocele of the vermiform appendix is an extremely rare condition and also a rare cause of an acute abdomen with a clinical presentation that is indistinguishable from acute appendicitis, and thus, the condition is diagnosed during operation. Here, the authors describe the case of a 78-year-old female, who presented with intermittent abdominal pain. The appendix had a pelvic position and the torsion was counterclockwise. In addition, the torsion was associated with mucocele of the appendix, which was considered a secondary factor of torsion. Appendectomy and drainage were performed.

Overexpression of peptidyl-prolyl isomerase Pin1 attenuates hepatocytes apoptosis and secondary necrosis following carbon tetrachloride-induced acute liver injury in mice

Pin1, a member of the parvulin family of PPIase enzymes, plays a crucial role in the post phosphorylation regulation that governs important roles in the cell signaling mechanism and regulates a variety of cellular events. In this study, we investigated the role of Pin1 in carbon tetrachloride (CCl4)‐induced apoptosis and necrosis of hepatocytes during acute liver injury of mice. An in vivo study was done with the overexpression of Pin1 in the mouse liver; using Pin1‐adenoviruse (ad‐Pin1) followed by CCl4 injection to induce acute liver injury. Pin1 overexpression in the liver of the experimental mice attenuated acute liver injury induced by CCl4. Serum aminotransferases and the number of apoptotic cells were decreased compared to those of control virus injected mice. In addition, Pin1 overexpression increased NF‐kB activity, as evidenced by increased DNA binding. In conclusion, Pin1 reduces acute liver injury of mice due to CCl4 by modulating apoptotic signals and by increasing NF‐kB activity.

Extradigit glomus tumor causing abdominal pain -a case report-.

Glomus tumors are small vascular tumors that are usually benign and rarely occur. They originate from glomus bodies and present in the reticular dermis. They are clinically distinguished by their small size and their ability to cause extreme pain. Most of these tumors are subungually located. However, atypical locations of the tumors sometimes cause misdiagnosis, particularly when the lesion is rarely reported. Therefore, we report a case of glomus tumor which presented with chronic abdominal pain, found in the abdominal wall that has never been reported before.

Involvement of prolyl isomerase PIN1 in the cell cycle progression and proliferation of hepatic oval cells

Liver regenerates remarkably after toxic injury or surgical resection. In the case of failure of resident hepatocytes to restore loss, repopulation is carried out by induction, proliferation, and differentiation of the progenitor cell. Although, some signaling pathways have been verified to contribute oval cell-mediated liver regeneration, role of Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1(Pin1) in the oval cells proliferation is unknown. In the present study, we evaluate the role of Pin1 in oval cells proliferation. In our study, the expression of Pin1 in the mice liver increased after three weeks feeding of 3, 5-diethoxycarbonyl-1, 4-dihydrocollidine (DDC) diet along with the proliferation of oval cells. The expression of Pin1 was higher in oval cells compared to the hepatocytes.Pin1 inhibition by Juglone reduced oval cell proliferation, which was restored to normal when oval cells were treated with IGF-1. Consistent with increased cell growth, expression of Pin1, β-catenin and PCNA were increased in IGF-1 treated cells in a time dependent manner. In FACS analysis, siRNA-mediated knockdown of the Pin1 protein in the oval cells significantly increased the numbers of cells in G0/G1 phase. Furthermore, hepatocyte when treated with TGF-β showed marked reduction in cell proliferation and expression of Pin1 whereas this effect was not seen in the oval cells treated with TGF-β. In conclusion, Pin1 plays important role in the cell cycle progression and increase oval cells proliferation which may be crucial in chronic liver injury.

Abdominal fibromatosis in a young child: a case study and review of the literature.

Fibromatoses comprise many different entities of well-differentiated fibroblastic proliferation with variable collagen production and form a firm nodular mass. Abdominal fibromatosis is distinguishable from other forms of fibromatosis because of its location and its tendency to occur in women of childbearing age during or following pregnancy. Abdominal fibromatosis in children is an extremely rare condition. A 15-month-old boy presented with an abdominal wall mass that had recently increased in size. Mass excision was perfomed. The tumor was 4.3×4.1 cm and partly circumscribed. Histologically, the tumor was composed of parallel long fascicles of spindle-cells with a uniform appearance. The edges of the resected mass were infiltrative, and the surgical margins were positive. Mitotic figures were <1/10 high power fields. No cellular atypia or necrosis was present. The tumor cells were positive for vimentin and nuclear β-catenin staining.

The fate of hepatocyte cell line derived from a liver injury model with long-term in vitro passage

BackgroundsOrthotopic Liver Transplantation (OLT) is the therapy of choice for the treatment of end-stage liver disease, but the severe shortage of organ donors, complex and expensive surgical procedure and increased mortality of prospective organ recipient limit the use of OLT. To overcome this problem the technique of hepatocyte transplantation has been considered as an alternative to OLT. Hepatocyte transplantation is less invasive, cost effective cryo-preservable and can be distributed from single donor to multiple recipients. In this study we have established and characterize the hepatocyte cell line possessing the morphological and functional characteristics of hepatocytes from chemically injured liver. Hence we hypothesized that the hepatocyte cell line derived from liver injury can be used for hepatocyte transplantation.MethodsTo induce the priming of hepatocyte, mice were fed with 3,5-diethoxycarbonyl-1,4-dihydro-collidine (DDC) diet for 3 weeks and hepatocytes were obtained by two step collagenase perfusion method, hepatocytes hence obtained was expended by >300 passages and tested for various hepatocyte specific functions.ResultsThe cell line derived from liver injury model retains morphological and functional characteristics of hepatocytes in long-term in vitro culture. These cells transplanted to mice showed significant survival rate.ConclusionThe Hepatocyte cell line derived from liver injury model were used for hepatocyte transplantation and showed the significantly higher survival rate.